public class Demo11 {
    public static void main(String[] args) {
        double d = 12900000;
        System.out.println(d); // 1.29E7
        double d1 = 3.1415926;
        System.out.printf("%.2f\n", d1); // 显示两位小数3.14
        System.out.printf("%.4f\n", d1); // 显示4位小数3.1416
        int n = 12345000;
        System.out.printf("n=%d, hex=%08x", n, n);
    }
}
